25 lines
525 B
Markdown
25 lines
525 B
Markdown
---
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title: deepFreeze
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tags: object,recursion,intermediate
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---
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Deep freezes an object.
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Calls `Object.freeze(obj)` recursively on all unfrozen properties of passed object that are `instanceof` object.
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```js
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const deepFreeze = obj =>
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Object.keys(obj).forEach(
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prop =>
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!(obj[prop] instanceof Object) || Object.isFrozen(obj[prop]) ? null : deepFreeze(obj[prop])
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) || Object.freeze(obj);
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```
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```js
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'use strict';
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const o = deepFreeze([1, [2, 3]]);
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o[0] = 3; // not allowed
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o[1][0] = 4; // not allowed as well
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``` |